A friend from Europe has asked me to help him fix his Sebring gear aluminum T10M transmission that pops out of third gear. I know that's a common issue with the T10 and seem to remember a part sourced from a modern transmission(maybe a Muncie) that corrects that issue.
1) Is the improved/modern component that fixes the issue called a hook slider?
2) Who is the current T10 guru and how can we make contact with him?
Thank you, Paul Marvin @817-691-0159, paulrmarvin@icloud.com .
Quote from: paul on September 24, 2025, 03:18:58 PMA friend from Europe has asked me to help him fix his Sebring gear aluminum T10M transmission that pops out of third gear. I know that's a common issue with the T10 and seem to remember a part sourced from a modern transmission(maybe a Muncie) that corrects that issue.
1) Is the improved/modern component that fixes the issue called a hook slider?
2) Who is the current T10 guru and how can we make contact with him?
Thank you, Paul Marvin @817-691-0159, paulrmarvin@icloud.com .
Make sure that interference with anything close to the shifter handle is not an issue. A friend of mine rebuilt his transmission completely only to find that his carpet was hard against the shifter handle.
John
Paul,
The torq-lock slider is the one you are looking for. See this ebay link for an available example:
SYNCHRO SLIDER (TORQUE LOCK DESIGN) - T10 | eBay https://www.ebay.com/itm/261835017475?chn=ps&mkevt=1&mkcid=28&google_free_listing_action=view_item&srsltid=AfmBOoq0Hz4S-xCZ6ImlITSJsdFXRVttFn8uR6p9RyXCKKWH6CbX91C7umY
Dave
Quote from: paul on September 24, 2025, 03:18:58 PM. . . . . T10M transmission that pops out of third gear. I know that's a common issue with the T10 and seem to remember a part . . . . . that corrects that issue.
I wouldn't say that "popping-out" is just a "common issue for "T10's", but rather that popping out of gear is not an uncommon problem for "most" manual transmissions, that are worn to the point of needing proper servicing; this perhaps vs. some 'trick part' (which may create other issues ::) ) as a solution. :)
Scott.
Quote from: pbf777 on September 24, 2025, 07:29:15 PMQuote from: paul on September 24, 2025, 03:18:58 PM. . . . . T10M transmission that pops out of third gear. I know that's a common issue with the T10 and seem to remember a part . . . . . that corrects that issue.
I wouldn't say that "popping-out" is just a "common issue for "T10's", but rather that popping out of gear is not an uncommon problem for "most" manual transmissions, that are worn to the point of needing proper servicing; this perhaps vs. some 'trick part' (which may create other issues ::) ) as a solution. :)
Scott.
Scott unfortunately for myself and many others with 65 and 66 GT350's the T10 popping out of gear is a pretty darn common issue as trans issues go experienced and observed.
I had the same problem in 3rd with my T10L and finally fixed it by replacing the cracked aluminum tail housing. Very common with the longer "L" tail.
Quote from: Bob Gaines on September 24, 2025, 09:18:56 PMUnfortunately for myself and many others with 65 and 66 GT350's the T10 popping out of gear is a pretty darn common issue as trans issues go experienced and observed.
I do understand the issue, as I have been in the business that included rebuilding transmissions, this including T10's and I've never had one have this problem once "properly" rebuilt and installed. 8)
"Knock on wood"! ::)
The cause can stem from several different possible issues involving several different component parts and of course a combination of the many, but simply stated it most often involves a failure to maintain component positioning and alignment under load and exacerbated with torque reversals, this generating a resultant trust effect which then leads to the ejection of gear engagement. This, as in the T10 example (and shared by many others), being most often evident with the 3rd gear as it is by design the unit on the mainshaft furthest from the main case support bearings and closest to the separation between the input shaft & drive gear (to the cluster) unit and the main/output shaft this where the greatest sum of displacement is present and seems is intended to be controlled by the bridge of the intermediate bearing but actually involves the fitment of everything in the distance from the input shaft pilot bearing to the tailshaft bushing to driveshaft slip-yoke fitment. :o
Over the decades there have been many different engagement ring tooth profiles with specific intentions, but this "trick" profile creating a differential of angles in order to create what by the original engineering intent would be excessive specific loading in the relationship, this proving the "grip" or as stated "torque lock" effect, just seems like a bad idea for a number of reasons and kinda like the old adage of "two wrongs attempting to make a right"! :-\
Now, is the B.W.T10 transmission the best and strongest light vehicle transmission ever created? Certainly not; but it also wasn't that bad either! But whatever the case, I just don't recall any comments being printed in period from the likes of say . . . . Ken Miles or others, that proficient shifting the T10 was problematic do to the "bungee cord" being in the way! ::)
Scott.
you have been very fortunate.
to clarify: this discussion is about a 2:36 'Sebring box"' T-10m/l. vice the contemporary 2:43 super-t-10 installed in a phony T-10m cast housing currently allowed in vintage racing.
A lot of the problem these days and particularly in racing is that the "End-Users" are expecting performance delivery capabilities from the engines coupled with suspension and tire "bite" that far exceeds that which the original drivetrains, and with the transmission caught in the middle, were ever intended to encounter; hence much of the problems and bad press that they receive today, of course coupled to sometimes not so expertly rebuilding and installation executions. :)
So, if any of this seems relevant to one's scenario, perhaps this might actually prove to be the "first wrong", and in performance/racing scenarios we (yes, myself included ::) ) often practice the second as a "fix"! :o
Staying within the design constraints as originally set forth by B.W., I always felt one of the biggest blunders was the choice in the utilization of the aluminum rear bearing support bracket or "mid-plate". It may have made sense in the aluminum case examples where weight might have been of greater concern, but with the load increases created as the engines became more powerful and the chassis got heavier, the writing was on the wall, and they swapped some to cast iron cases & tail housings (not necessarily in that order) but didn't change this aluminum bearing retainer for steel or iron. :o
Scott.
I never had problems with third gear but occasionally with downshifting to second.
WOW!
Any responses to question #2?
Paul,
Regarding #2 try John at Cobra Automotive.
~Earl J
There is also Mike Miles, either in WI or IL. I'll look for his contact info.
Joe
I sent Mikes contact info to Paul
Okay
Quote from: Rickmustang on September 26, 2025, 09:31:58 AMI sent Mikes contact info to Paul
I know that others can do the fix also but Mike has successfully done it for me and many others.Jim Cowles R.I.P. swore by him.
Thank you guys. I got Mike Miles' phone number and endorsement from Jesse Bourdeau three days ago and left a voice message but no response as of yet. I'm certain he's who I'll be working with when he does. Paul.
Orrrrrrr...ever consider putting in a brand new state of the art TREMEC
much stronger, brand new everything, better gearing, great over drive, faster acceleration, better MPG on the highway, running at idle at 90 MPH
about $3 to 5,000 for a complete tranny and conversion kit
put your old box away or in a museum for display
put an original shifter in it making it look authentic to all passersby....
Best of luck in your endeavors